By moving slime or honey blocks in the most recent snapshot, they seem to 'disappear' for a short amount of time, allowing interaction with the blocks behind, and causing certain blocks to become invisible. This is most evident when the blocks are moving rapidly. As far as I have tested, this bug causes the following blocks to become invisible:

• Water
• Portal blocks (Nether and End)
• Stained glass
• Stained glass panes
• Signs
• Banners
• Smoke particles
• Slime and Honey blocks

Likely more, but this is all that I tested.